Rainbow was the house band for the Wilmington South club in Dayton (Kettering). The band was led by lead singer Marvin Smith, who had been in the Triumphs. He had a couple different female singing partners, Beverly Sutton and later Kathy Crawford. The other band members were Jim Payne, Mark Fitzpatrick, Rick Aracri (drums), and Jim Browning.
The band made a 45, probably in 1973, with a funk instrumental A side "Do What You Wanna'". The record was issued on custom label for Wilmington House and pressed at the infamous Richmond Plastics styrene plant.
Based on some paper searching, Rick Aracri had been in Stone Hinge and the Aggragate Society before Rainbow.
That's all we know for now.
Do What You Wanna' / Buffalo Soldier - Wilmington House 1, 1973